Seal for bung rings



May 12, 1942.

J. R. PROCTOR SEAL FOR BUNG RINGS Filed Aug. so, 1938 2 Sheets-Sheet 1 May 12, 1942,

J. R. PROC'TOR SEAL FOR BUNG RINGS Filed Aug. 30, 1938 2 Sheets-Sheet 2 Patented May 12, 1942 PATEN T Fics SEAL FOR BUNG RINGS John R. Proctor, Bayonne, N. J., assignor to Atlas Steel Barrel Corporation, Bayonne, N. J., a corporation of New Jersey Application August 30, 1938, Serial No. .227,601l

Claims. This invention relates to sealing metal containers against unauthorized opening and has particular reference to `a means for sealing the plugged bung iiange of metal drums in such manner as to preclude undetected removal of the plug to permit access to the contents of the drum.

An object of the invention is to effectively seal the plug against undetected access by means of a simple, inexpensive seal-cap and to so construct and arrange the seal-cap and the bung ange to which the cap is secured that the latter may be rapidly positioned in the flange without need of laborious centering, and subsequently locked in4 place rapidly and with a minimum of effort on the part of the worker.

An important feature of the invention resides in tle ease with which the seal-cap may be applied and the simplicity of the operation by which it is locked in place. In accordance with the present invention the sealecap is simply dropped in a recess provided therefor in the outer surface of the bung ange. The cap is provided with a peripheral iiange Which may then be expanded or forced radially outwardly into an undercut portion or cleft extending around the periphery of this recess, thereby locking the cap in its seat.

Other important features of the invention reside in the particular construction and arrangement of parts whereby the above objects are attained, the simplicity and ruggedness of the mechanism for accomplishing the same, land the effectiveness of the joinder between seal-cap and flange.

Various other objects and meritorious features of the invention will be apparent from the following description taken in conjunction with the drawings, wherein like numerals refer to like parts throughout the several figures, and wherein:

Figure 1 is an elevation of one form of tool adapted to perform one step of the method disclosed herein;

Fig. 2 is a, fragmentary elevation, partly in section, illustrating the position of this tool after expanding the seal-cap into locking engagement with the bung iiange;v

Fig. 3 is a section along 3 3 of Fig. 2;

Fig. 4 is a section illustrating the initial step in operatively positioning the seal-cap in the bung flange;

Fig. 5v is a section similar to Fig. 4 with the seal-cap expanded into locking engagement with the bung flange;

(ci. 22o-,39)

Fig. 6 is a-fragmentary elevation of a somewhat modied form of tool;

Fig. 7 is a section along '1 1 of Fig. 6;

Fig. 8`is 'an elevation, partially in section, of a modified form of seal-cap prior to-expansion into locking engagement;

Fig. 9 is a similar View showingfthe form assumed by this modification after using the tool illustrated .in Fig. 6, and

Fig. 10 illustrates `in section a detail of the tool.

Referring now to Fig. 2 of the drawings, the reference numeral I0 represents the metal stock of a drum provided with an aperture adapted to receive a bung assembly. A bung ring having a flange I2 and internally threaded to receive plug It is positioned within the aperture in any suitable manner. As here shown the shank of the bung is extruded or expanded radially outwardly as indicated at I4 to grip the metal of the barrel stock immediately surrounding the aperture, together with backing ring I6, firmly between the extruded portion and the flange. Rotation of the bung ring with'- in the aperture may be prevented by any suitable means, here shown in the form of biting surfaces I8 around the exterior of the bung ring shank immediately below the flange which are expanded into biting engagement with the side wall of the aperture vand with the side wall of the backing ring I6.

The upper surface of flange I2 is provided with a recess having an undercut or cleft 22 extending around its periphery. While the angle of undercut is not of paramount importance, I have determined that is satisfactory.

One form of seal-cap suitable for my improved method of application, and adapted for use with the tool illustrated in Figs. 1-3, is indicated by the numeral 24. It comprises a crown portion 26 preferably rounded as indicated at 28 into a vertical side wa1l30 and having an annular fiange 32 with an angle piece 34 extendingaround the outer periphery thereof. The cap may be sheet metal and stamped in a single piece.

Plug I4 having been threaded into the bung ring, seal-cap 24 is dropped into the seat formed in the upper surface of the bung flange by recess 20. The seal-cap is so dimensioned that in performing this operation the outer periphery thereof just clears the upper tip of the 45 undercut indicated at 22. It is therefore apparent that the cap may be applied rapidlyand easily, there being no need for centering or adthe supporting lip 42 which justing the same with reference to the bung assembly prior to locking the cap to the flange.

The angle piece 34 is then expanded radially outwardly into the undercut 22 of recess 26, thereby iirmly locking the cap in the ange and precluding access to the drum by removal of the concealed plug without first removing the seal-cap. Such-removal would be readily detected and thus the consignee of the drum contents would realize tampered with.

One form of tool for expanding this type of seal-cap into locking engagement with the bung flange is illustrated in Figs. 1-3. rilhis tool comprises a housing 36 open at the base and having that the drum had been a skirt 38 externally threaded around the lower i portion thereof to receive an internally threaded collar 40 which is provided with a lip 42 extending radially inwardly beyond the skirt 38. Four segmental expanding members 44 are positioned within the housing for radial movement therein. An endless coil spring 4B positioned withinalined grooves 48 in the outer walls of the expanding members tends constantly to contract them.

The inside face of each expanding member is tapered along spaced portions as indicated at 50 and E2, thereby formingl in the aggregate an upper cone and a somewhat smaller lower cone for a purpose to bemore clearly brought out hereinafter. Contraction of the expanding members 44 is limited to such movement as will bring the vertical faces 54 of the inside bottom wall portions of each segment into contact with one another. This movement is not sufficient to permit the said expanding members to drop through retains them in the housing.

A casing sleeve 56 is threaded into an annular groove 58 in the top of casing 36 and an apertured cap E!! is threaded as indicated at 62 onto the upper end of the said casing sleeve. Plunger 64 is slidable through the aperture in cap 60 and is provided with a reduced portion 66 adjacent its lower extremity adapted to slide through an opening in the top of housing 36. The shoulder 68 formed by the reduced lower portion of the plunger clears the top of casing 36 when the plunger is fully depressed. A slidable collar 10 is adjustably positioned with reference to plunger 64 as by means of set screw 12, which collar provides an upper seat for coil spring 14, the bottom of which seats on housing 36, thereby providing a constant force tending to urge the plunger to the upper limit of its movement. In the particular form illustrated the upper portion of the plunger is reduced in diameter to form a shoulder 16 which provides a stop for collar 18 slidlably positioned on the upper reduced portion of the plunger and adjustable with reference thereto by means of set screw 80. A heavy cast iron ball 82 is slidable along the upper reduced portion of the plunger, its upper limit of movement being marked by collar 84 which is preferably 4slidable land 'adjustable with reference to the plunger.

The under side of housing 361 is provided with a recess 83 for seating the upper cylindrical portion 83 of a generally cone-shaped cam 90 integral with or secured to the bottom of the plunger, the taper of which corresponds to the taper of spaced cone seats 56 and 52 formed by the segmental expanding members. These cone seats are separated by a straight-walled portion 92 which forms a seat for the cylindrical wall portion 88 of the cam cone.

Each segmental expanding member 44 is provided with peripheral toe portions 94, the hypotenuse of each of which is somewhat rounded, as indicated in somewhat exaggerated form in Fig. l0 at 96, to facilitate the expanding action thereof in locking the seal-cap in the undercut of the bung flange.

In operation the seal-cap 24 is rst dropped into recess 20 as indicated in Fig. 4. The weight of ball 82 ovecomes the normal upward thrust of spring 14 to retain cam cone 90 in its lower seat when the tool is not in use, thus forcing the expanding segments outwardly against the tension of coil spring 48 to prevent relative movement of the parts and consequent wear and tear. When seal-cap 24 is to be expanded into locking engagement, ball 32 is lifted to remove its weight and permit coil spring 14 acting on collar 10 to urge the plunger to its uppermost position, the limit of upward movement being reached when cam cone 90 seats in socket 86 provided therefor in casing 3S. As cam cone S0 moves to its upper seat, spring 45 contracts the expanding members. When the tool is contracted the inside of toe portions 94 just clear the rounded crown 28 of the seal-cap, which is somewhat higher than angle portion 34 of the seal-cap flange. This rounded crown therefore functions as a guide to prevent the toes ofthe expanding segments from fouling the upper edge of angle piece 34 when the sealing tool is positioned. The toes 94 being seated on flange 32 of the seal-cap, the collar 18 is struck forcibly by sliding ball 82 downwardly. This forces the plunger downwardly and cam cone Si) operates against the tapered seat of lower cone 52 to expand the segments. During expansion the toes 94 force the upturned edge 34 of the seal-cap into the undercut 22 of the recess provided in the bung ange.

The tool is released by again lifting ball 82, thereby permitting the spring 14 to lift cam cone 90 into its upper seat which in turn permits spring 46 to contract the expanding segments.

The rounded hypotenuse Sii of toes 94 on the expanding segments tends to draw the vertical line of the seal-cap rim downwardly while the base ange 32 remains seated in the recess 26. The metal in seal-cap flange 32 and its rim or angle portion 34 is preferably sufficient to leave an inturned marginal rim portion 98 within the cleft provided by undercut 22, thus rendering unauthorized removal of the seal-cap still more dicult.

A somewhat modified form of seal-cap is illustrated in Figs. 8 and 9. Fig. 8 illustrates the structure prior to expansion into the flange recess. This form of cap is provided with an outwardly extending marginal skirt or ange |00 which is, like the previously described cap, selfvcentering in that its diameter is slightly smaller` than the inside diameter of recess 2@ in the bung ange, thereby permitting the cap to readily find its seat.

A tool such as that illustrated in Figs. 6 and 7 may be employed for expanding this form of cap, for which operation a square ring face |02 may be used. In the form illustrated this ring face is supported by a plurality of arms |04 integral with or connected to a handle IE6 which is preferably weighted by a ball |08.

After dropping the cap in its seat, ring face |02, the diameter of which is slightly greater than the diameter of the upper cylindrical portion of the cap, is brought down over said upper portion into engagement with skirt portion |00.

Continued downward movement of the tool forces the said skirt radially outwardly into the undercut or annular skirt is squared out into a peripheral ange H0 extending at right angles to the cylindrical upper portion of the cap and no inturned marginal rim portion such as that illustrated at 98 in Fig. 5 is obtained.

While other than that illustrated in Figs. 6 and '7 may be conforms the wall metal of the seal-cap to any slight irregularities in the dimensioning or workmanship of the cleft 22. If the margin of flared skirt |00 seats in cleft 22 before the flare has been shifted to form substantially a right angle as illustrated in Fig. 9, continued movement of the ring along the wall of the seal-cap will so deform the metal as to and decreasing the width of the peripheral ange I l 0.

While in this application I have disclosed certain preferred means for locking the seal-cap in be apparent to that reason I an upwardly extending angle piece.

2. A seal cap for closing the opening in a bung ring, said cap comprising a crown portion having the crown portion.

3. A seal for a bung ring having an outwardly disposed flange comprising, in combination, a recess in the outer face of said ange, an out- 4. A seal for a bung ring having an opening and an outwardly disposed ange comprising, in Combination, a recess in the outer face of said 5. A bung ring having an opening therein and a flange at one end, said flange including yan JOHN R; PRocToR. 

